Let me preference this with, I don’t speak Welsh (yet), I live in the US, and I’ve never been to Wales. Feel free to skip this comment if you so desire.
Honestly, I think Welsh faces the same sort of issue in Wales that Mexican immigrants (we’ll go with that, since I’m in Texas, and not, say Florida or NY), have in Texas getting their children and grandchildren to continue to speak Spanish. Same issue with hearing children of deaf parents in this area. Saw the same issue with a Chinese family at a preschool I worked at. It’s a similar trend all around. 1st generation speaks it, 2nd generation speaks it as a home language and also speaks the common language of the area they are raised in, 3rd generation doesn’t speak it at all.
I could go into all the stuff linguists talk about, but what it comes down to is…the 1st generation has the home culture, social groups, as well as services they rely on, that demand they speak that language. The 2nd generation may be forced to speak it at home, but elsewhere? It’s useless to them. So they don’t bother teaching their children. Whether or not is has to do with identity or culture, the language just slips while other parts of the culture remain.
Wales is unique in that you’ve got the primary/elementary (I’m not sure what you call it in the UK. Anyhow, little kids, ages 5-12 or so) schools teaching it, which is a huge boost, so you’ve got the young speakers without having to rely on parents 1) knowing Welsh 2) making it the home language. So I’m guessing what you are lacking are main stream services and social circles that demand speaking in Welsh outside of school. Like, say, making the local football club for kids Welsh only, both in casual chatter and in instruction. Having local restaurants go Welsh only unless requested otherwise. Having Welsh speaking adults…speak Welsh! Try Welsh first when encountering a new face or business. Speak Welsh first to children, and continue to speak Welsh even if the kids’ Welsh isn’t that great.
I think that’s why I picked up American Sign Language so quickly, we didn’t have the option of just reverting to spoken English, and texting back and forth in the aisle was too slow.
It’s really a huge effort by lots of people to make speaking Welsh (or Spanish or whatever) outside the home something commonplace. And not just commonplace. Spanish is common place in Texas. But it is not necessary in the least. I can go to an all Spanish speaking part of town for barbacoa (don’t look that up), and I can still order in English. I could use what little Spanish I have but, honestly, a month with SSIW has given me more useful things to say in Welsh than I have to say in Spanish, and I have taken 7+ years of Spanish in my life (and lived about 6 months in Mexico), with endless opportunity to speak it (but why bother? The only time I really needed Spanish was on a construction site when all the directions “climb down the ladder and get the hammer” were in Spanish, so it was figure it out or stand around stupid). Again, I know more useful things in sign language than in Spanish because when you need to use sign language it YOU HAVE TO USE IT or else you don’t get to have that conversation.
My thought? Make Welsh a necessity. Humans will always do the lazy thing (revert to most common shared language) so you have to make Welsh the price of entry into things kids really want, and continue to keep it relevant that way as people grow up. (I won’t pretend I have any specific ideas on that lol)
Another thought, about adapting English words into Welsh. I think it’s pretty neutral. The French are so hard core about not adopting words into French officially…but everyone uses them anyhow. And where are the most French speakers, and where is French growing fastest? Northern Africa! Where they don’t care for France’s very strict rules on importing loan words. Where French is growing best while it adopts all sorts of new words for a ton of different reasons.
Look at English, what is that quote about English not just borrowing words from other languages, but following them down dark alleys, knocking them out, and rifling their pockets for words? The bigger Welsh gets, now, the more loan words it’s bound to import, and I think that’s just fine. Restricting that will restrict the utility of a language to be a language. Been watching PYC last few days and it’s a riot watching the characters be like “Ok, reit, plis, chill” and then carry on in Welsh at top speed. lol